Achira Kochira Bokura (no, Arekara to Korekara)

Majima and Sonoki have gone a long, long way from being just classmates from different cliques with a budding, bumbling friendship. Now living separate lives at distant universities, they haven't talked since graduating high school—but for some reason, they can't help but think that something very important is missing. Taking matters into his own hands, Sonoki pours his emotions into a letter he swears will never get read—but what happens when Majima actually gets his hands on it?

(Source: Fantasista Inc.)